The present invention relates to agricultural tillage tools such as rippers, and more specifically to trailing implements for such tools.
Rippers have been used to fracture soil and eliminate soil compaction without substantial destruction of the soil surface. Rear mounted soil conditioning attachments such as disk levelers are commonly used to provide a leveling function behind the ripper shanks. The attachments are typically raised and lowered with changing soil conditions or varying soil conservation requirements within a field.
Double acting cylinders or mechanical adjusters are used to maintain the attachments in a generally fixed position relative to the ripper frame. If the tractor selective control valve (SCV) is placed in the neutral position or if mechanical height adjusters are used, the attachment can be locked relative to the frame and generate extremely high loads through the frame members when the implement travels through a ditch or other depression or if the rear attachment is set too deep. Depth problems are particularly acute in ripper tools since the ripper standards aggressively pull the machine into the ground. Most rear mounted attachments for rippers have limited flexibility, and in some ground conditions one side of the attachment tends to dig too deeply while the other side lifts from the ground. Cushioning springs are often required for limiting problems with excessive force transfer and depth control. Attitude of the trailing attachment tools changes with changes in vertical position of the attachment relative to the implement frame with single link arms.
It is therefore an object of the present invention to provide an improved trailing attachment for a ripper or similar agricultural implement. It is a further object to provide such an attachment which overcomes most or all of the above problems.
It is another object of the present invention to provide an improved trailing attachment for a ripper which has better overload protection than at least most trailing attachments. It is another object to provide such an attachment which is adjustable hydraulically and yet which is flexible regardless of the SCV position while operating in the field. It is another object to provide such an attachment wherein flexibility and overload protection are provided independently of cushioning springs.
It is still another object of the present invention to provide an improved leveling attachment or similar trailing assembly for a ripper or other agricultural trailing implement arrangement which is simple in construction, has good flexibility and depth control characteristics, and provides some adjustability on-the-go from the tractor cab. It is another object to provide such an attachment which can be supported in a relatively fixed position above a mechanically set down stop position without inducing excessive loading on the supporting implement when traversing uneven terrain.
A trailing attachment for a deep tillage tool such as a ripper includes a toolbar supported by first and second transversely spaced four-bar linkages extending rearwardly from the ripper frame. Connected between upper and lower links on each of the linkages is a single acting hydraulic cylinder having a base end connected to a source of hydraulic fluid under pressure through the tractor SCV. The base ends of the cylinders are pressurized to adjust the attachment vertically and raise the attachment out of the ground. The trailing attachment has sufficient weight for desired tool penetration of the ground independently of any down pressure springs. A mechanical depth stop, such as donuts mounted on the rod ends of the cylinders, or similar conventional device sets maximum depth.
To raise the trailing attachment, the SCV is moved to pressurize the base ends of the cylinders. A breather plug and a U-shaped hose connected to the rod end allows air to be pushed from the rod end as each cylinder extends. To lower the trailing attachment, the SCV is moved to open the base ends of the cylinders to the return line of the hydraulic system, and the weight of the attachment moves the tools into the ground until the maximum depth is reached. The operator can raise the attachment above maximum depth set by the depth stop by pressurizing the base ends of the cylinders and then putting the SCV in the blocking or neutral position. If for any reason the vertical lifting force on the attachment exceeds the weight of the attachment, air is pushed out through the breather plug and a vacuum is drawn in the base ends. The attachment can lift, even if the SCV is in neutral and blocking fluid flow into the base ends, to avoid excessive frame loading when going through a depression or when the ripper lowers because of the action of the ripper shanks pulling the machine too deeply. Each linkage can move a limited amount relative to the other linkage for flexibility over uneven terrain. Because protection is built into the hydraulic system, overload cushioning springs are not required. The system is simple in construction and operation and provides necessary flexibility, adjustability, and overload protection for a trailing implement, even when operating in fields with changing ground conditions and extreme surface contours. Attitude of the trailing attachment tools remains unchanged as vertical position of the attachment relative to the implement frame changes.
These and other objects, features and advantages of the present invention will become apparent to one skilled in the art upon reading the following detailed description in view of the drawings.